1. Field of the Invention
This invention relates to a new and improved tuning device for use in tuning a musical instrument. More particularly, this invention embodies features which permit it to tune a class of acoustic musical instruments, such as acoustic guitars, in an exceptionally convenient manner.
2. Description of the Prior Art
Described in the prior art are many devices intended to facilitate the tuning of acoustic musical instruments. They include the pioneering tuner disclosed in Krauss, U.S. Pat. No. 2,806,953, in which a stroboscopic disc, spinning at a precisely controlled reference rate of rotation, is illuminated by a neon lamp which is caused to flash at the frequency of an unknown musical tone. A stationary pattern, indicating an in-tune condition, is observed when the frequency of the unknown tone is equal to the rotational frequency of the disc. If the tone is flat, the pattern will appear to rotate in a first direction at a rate proportional to the amount of deviation of the tone from the reference rate. If the tone is sharp, the pattern will appear to rotate in the opposite direction. Despite the bulk and weight of this early vacuum tube driven electromechanical device, as well as the need to power it from 120 VAC, it became a tuning standard for many years.
With the emergence of microelectronics, and especially the availability of the single chip microprocessor/microcontroller, more recent tuning devices have appeared which enable the tuning of acoustic instruments with enhanced portability and utility. An example is the electronic tuning device of Miller, et al., U.S. Pat. No. 5,388,496. This device includes a row of twelve light emitting diodes (LEDs) which correspond to the twelve musical semitones, tone sensing circuitry which is optimized to receive a musical tone through a double back adhesive rubber pad and provide a representative electrical signal, and a single chip programmed microprocessor which operates to determine the fundamental frequency of the electrical signal. Based on the difference between the fundamental frequency and an internal reference frequency, the microprocessor lights that one of the twelve LEDs which is closest to the unknown tone and blinks it at a rate proportional to the difference in the frequencies. Tuning direction is annunciated by causing the selected multi-colored LED to display a first color if flat, a different color if sharp, and yet another color if in tune. To function properly, this tuner must be stuck, by means of its adhesive pad, to the musical instrument.
Generally speaking, prior art tuning devices have appeared in a multitude of shapes and have had varying degrees of portability. Typically they have been either housed in stand-alone enclosures or, else, housed in enclosures which must be physically mounted to the musical instrument in order to function.
Despite their utility, the stand-alone acoustic tuning devices have been awkward to use. Characteristically, in order to acquire the musical tone with a sufficient signal-to-noise ratio, these tuners must be placed in near proximity to the musical instrument. As a result, the musician seeking to tune his instrument must place the tuner on a supporting surface such as a tabletop or music stand and hold his instrument dose to it.
The need to have a supporting surface nearby in order to prop up a tuner imposes a substantial limitation on a musician's freedom of movement. Even in performance, where a music stand may be available, a tuner placed on it can be accidentally knocked off and suffer damage, or it may obscure part of the music. Most problematic, however, is the difficulty the musician has when attempting to use such a tuner in the presence of ambient noise such as can exist during a performance. Often, to increase the amplitude of the musical tone over the ambient level, an acoustic guitarist will resort to removing the tuner from the stand and place it closer to the soundboard of his guitar by balancing it on his knee—an extremely clumsy operation. Also, in many situations, the performing musician chooses not to use a music stand. A classical guitarist, for example, usually performs a concert without written music in front of him, and the presence of a music stand or other tuner supporting surface would be unacceptable.
In an attempt to eliminate the above problems several tuning devices have appeared which require the mounting of the tuner onto the instrument. The Miller tuner, supra, is one such example. The need to stick this tuner to the instrument with a double back adhesive pad in order for it to function, however, imposes its own set of limitations. For example: the majority of concert level classical guitars are finished with a very thin, and very delicate, layer of French polish of shellac in order to ensure that the quality of the sound developed by the instrument is not compromised by its finish. Having invested many thousands of dollars, a classical guitarist is, invariably, unwilling to risk marring the instrument's surface and will not stick anything onto it. Also, the rectangular shape of this tuner does not readily permit it to be mounted to a number of other acoustic musical instruments, such as a trumpet.